In the prior art, the shaped edge portions or flanges of metal panels used in roofing and/or siding, for example, are most often formed by use of hand tools. This procedure is laborious, time-consuming, wasteful of material and relatively expensive. Moreover, the hand-forming process frequently results in non-uniform and uneven seams, creating an unsightly and potentially leaky surface.
In an effort to reduce or eliminate the above problems, the builder or contractor may order and purchase preformed metal panels from a supplier. This solution, however, results in a relatively expensive panel due to the necessity of paying someone else to shape the panels and because of the increased storage, shipping and handling costs. Moreover, if the number and/or size of the preformed panels is miscalculated by the builder or contractor, delays in construction and further expenses may be incurred.
Various machines have been developed for forming metal roofing and siding panels, including some portable machines which may be used for on-site shaping of the metal panels. Such machines are exemplified in U.S. Pat. Nos. 2,294,324, 2,747,642, 3,462,989, 3,595,053, 3,788,115 and 3,823,592. With the exception of U.S. Pat No. 3,823,592, all of these patents describe machines which are constructed and intended to produce metal panels having a single predetermined shape. Some of the machines may be modified to produce metal sheets having different shapes by replacing individual sets of forming rolls. U.S. Pat. No. 3,823,592 does disclose a structure wherein a spine member carrying sets of forming rolls may be detached and replaced with a spine member carrying different forming rolls to impart different shapes to the metal being formed. The drive means for the rolls remains attached to the main frame of the machine, and individual coupling devices for each driven shaft and roll are provided. Panels formed by the machines must then be lifted onto the surface (roof) being covered with the panels.